Self-cleaning boiler control



Aug 19, 1941- o. F. CARLSON 2,252,962

SELF-CLEANING BOILER CONTROL Filed Nov. 30,4 1940 Patented Aug. 19, 1941SELF-CLEANING BoILER CONTROL Oscar F. Carlson, Kenilworth, Ill.,assigner of one-half to Oscar F. Carlson Company, Chicago, lll., acorporation of Illinois and one-half toy Everett` N. McDonnell, Chicago,Ill.

Application November 30, 1940, Serial No. 367,871 5 claims. V(C1.137-104) My present invention relates to self-cleaning boiler controlsand the like.

In the embodiment of my invention herein disclosed, I have shown anddescribed a float responsive boiler control device secured directly in fthe wall of a boiler with the present invention incorporated therein toassure that the control will be kept clean and function in its intendedmanner, but it will be understood that the invention may be readilyadapted to other uses and is not limited only to float responsivecontrols.

In boiler controls of the type noted, al shield must be provided toprotect the float from the ebullient boiler water. The chiefdisadvantage of this type of installation is that mud and other sedimentaccumulates and lodges within the shield interfering with the properfunctioning of the control and unless the shield is `frequently removedand cleaned the control cannot be de'- pended upon.

The primary object of my invention is toprovide a boiler control or thelike which is self= cleaning.

I provide, in the preferred embodiment of my invention, a supportingsleeve or easing, prefer`` ably of circular cross-section, whichmay beselcured directly in the boiler wall to extend out-'- wardly awaytherefrom and which, preferably, is adapted to support the entireAboiler control mechanism. A tubular shield is disposed Within the sleeveand defines a chamber in which a float member or other operatingmechanism is adapted to be disposed. The shield is of a suitable lengthso that one end portion thereof is adapted to extend within the boiler.The' shield, preferably, is of oblong or elliptical cross-section andthe major cross-sectional axis thereof preferably should besubstantially equal t'o or slightly less than the diameter of the sleeveand arranged so that this axis is vertically disposed in the-sleeve;With such a construction of supporting sleeve and shield it will be seenthat a passageway is formed between each side of the shield and the wallof the sleeve.

The bottom portion of the shield adjacent its end within the boiler isprovided with' a plurality of relatively small openings and a relativelylarge or relatively free opening is `formed in the' bottom of the end ofthe shield within the sleeve.y Thus when the sleeve is mounted in theboiler wall, one end of the shield is disposed in the hot boiler Waterand the other end of the shield is supported in the sleeve outwardly ofthe boiler wall. The sleeve which is outside the boiler wall loses heatby convection and radiation so that the water in the sleeve loses heatand becomes denser, drops toward the bottom and flows out. With such aconstruction, convection currents are set up so that the boiler waterwill ow through the passageways deed by the sides of the shield and theinside wall of the sleeve into the relatively large opening in the endof the shield Within the.

sleeve, along the inside bottom surface of the shield and then throughthe number of small openings in the bottom of the shield adjacent itsend disposed within the boiler. Thus, it will be seen that I haveutilized tlie physical property of the` varying density of water due torits varying temperature to cause a continuous convection current to flowsov that the botton of the shield is constantly being swept by theboiler water keeping the interior' of the shield clean.

It will be seen that if a float member such as is suitable for openingor' closing a switch member of a boiler control device, be disposedwithin the shield of my present invention, the constant sweeping actionwill prevent the accumulation of mud or sediment which would clog orinterfere with the float. Generally a bellows is incorporated with thefloat to allow the float to move in accordance with variations in liquidlevel and in such cases the Abellows will also be kept clean.

Other objects and advantages of my invention will be apparent from thefollowing detail de'- scription.

Now, in order to acquaint those skilled in the art with the manner ofconstructing and operating my invention, I shall describe in conjunctionwith the accompanying drawing a specific einbodiment of the invention.

In the drawing:

Figure 1 is a perspective view of a boiler control embodying myinvention;

Figure 2 is a longitudinal vertical section of the rboilercontrol ofFigure 1; and

Figure 3 is a vertical section taken Substantially on thev line 3-''3 ofFigure 2, looking in the direction indicated by the arrows.

Referring now to the drawing, I have shown my invention incorporated ina boiler control l which is adapted to be mounted directly in the wallof a boiler 2. A sleeve on casingr 3 preferably of circularcrossesectio'n and of any suitable length is threaded at one end, as at4, and is provided with an integral'ange 5 at its other end. Variouslengths of sleeves 3 may be provided'to meet the requirements of variousboilers. An annular mounting plate 8 seats in the open end of the sleeveadjacent the flange 5 and is secured to the latter by means of anannular flanged mounting ring 9 by means of cap screws I8. A gasket I2is interposed between the sleeve 3 and the plate 8 to provide a fluidtight seal. A tubular shield member I5 of substantially elliptical oroblong cross-section, the major crosssectional axis of which preferablyis substantially equal to the diameter of sleeve 3 is disposed withinthe sleeve 3 with the axis referred to extending substantiallyvertically, so that the sides I6 of the shield, together with the insidewall of the sleeve, define passageways I1-I1. The shield preferably ismade of a relatively thin sheet of copper, or copper alloy, or othercorrosion resisting material which is shaped, as above described, bypositioning the free edges -2Il of the sheet over each other andsuitably securing the edges together as by providing one of the edgeswith a plurality of integral spaced ears or tabs 2l, which are adaptedto be inserted through correspondingly spaced slots along the other edgeand then bent over. One end of the shield I5 is closed by means of awall member 23 which is fixed closely adjacent that end by means of aplurality of tabs or ears 24 integral with the member 23 which areinserted through slots in the shield and then bent over. The mountingplate 8 is provided with an integral flange 21 of substantially the sameconfiguration as the crosssectional shape of the shield I5 and extends ashort distance inwardly of the sleeve 3. The open end of the shield isfitted over the flange 21 and secured to lugs 28 formed integral withthe plate member 8, by means of screws 3U. A relatively large opening 3|is formed in the bottom portion of the shield I5 adjacent the platemember 8 and a plurality of small openings 32 are formed in the bottomof the shield adjacent its other end, the purpose of which will behereinafter described. A closure plate 35 is secured to the plate member3 by a plurality of cap screws 36 and a washer 31 is interposed betweenthese members to form a fluid tight joint. An annular supporting orclamping ring 38 is also secured in position by means of the cap screws36 and this supporting ring is adapted to have mounted therein brackets4I] for supporting a switch 4I. A switch housing 42 is fixed to theplate member 8 by screws (not shown) and this housing is provided withan outlet 43 for conductors extending from the switch to the mechanismto be controlled, such as a low water cut-off, or other device. 'I'hedetails of the switch and mounting thereof upon the plate member 8 arenot pertinent to the novelty of my present invention and a more detaileddescription. thereof may be found in my pending application Serial No.228,566, filed September 6, 1938, for Low water cut-off. A float 45preferably `of generally cylindrical shape is disposed within the shieldI5 which as before noted is of elliptical cross-section so that it mayaccommodate vertical movement of the float responsive to the liquidlevel of the boiler. A bellows 45 is secured to one end of the float andextends to a plate 41 which is welded or otherwise suitably secured tothe closure plate 35 so that boiler fluid can not enter the switchhousing 42. An operating arm or lever 5F! is pivotally mounted upon ahorizontally disposed pin 48 which is supported between a pair of ears43 formed integral with the plate 41. Lever 50 is connected at one endto the float 45 which is adapted to cause the lever 58 to pivot aboutthe pin 48 to actuate the switch lever 5I and plungers 52 and 53 of theswitch 4I responsive to the vertical movement of the float 45, as ismore fully disclosed in my above referred to application, to whichreference is being made.

The shield I5 should preferably be of a suitable length to accommodate aoat of the desired length. It is usually desired to dispose as much ofthe control within the boiler as possible in order to avoid the externalprojection of the device. Since boiler tubes or walls may limit theextent to which the shell or casing I5 can be extended inside theboiler, various lengths of sleeves 3 are provided. For best results theend of the shell or casing I5 should extend in to the wall space of theboiler far enough to uncover freely suflicient of the bottom openings 32to let mud and like impurities be Washed out. It will be seen that oneend of the shield being disposed in the boiler water will be maintainedat a relatively higher temperature than the other end and the sleeve 3since the latter are both outside the boiler wall and are cooled by theambient air. Thus, a convection current will be set up and boiler waterwill flow through the passageways I1-I1 where the water' will be cooledincreasing its density and causing the same to follow a downward pathoutwardly away from the boiler wall, as indicated by the arrows inFigure l. The water will enter the opening 3I of the shield and willflow along the inside bottom surface of the shield and out through theopenings 32 back into the boiler. This convection current will continueas long as there is hot water in the boiler at or above the level of thesleeve 3 so that mud or other sediment cannot accumulate within thefloat chamber defined by the shield I5 and plate 8 and foul the float 45or bellows 46. It will be seen that if a low water condition arises thefloat will drop actuating the switch 4I which may be connected, forexample, to a burner cut-off device so that the low water condition willnot damage the boiler.

I have tried inserting the control of my invention into position in aboiler with the casing I5 filled up solid with wet core sand. In asurprisingly short time the control cleaned itself completely. It willbe seen that the more time the liquid has to lose heat-within limits-thecooler the liquid in the outer part becomes. Hence, the greater changein density tends to create a stronger tendency to set up a circulation.

The boiler control herein described may be mounted in the boiler wall byscrewing the threaded end 4 of the sleeve 3 in the opening providedtherefor in the boiler wall. After the sleeve has been drawn up tightlythe tubular member I5, switch housing 42, and switch mechanism 4I, maystop in an out of vertical position. In order to adjust these severalparts in a vertical position, as shown in the drawing, it is onlynecessary to loosen the several cap screws IIJ and by grasping theswitch housing 42, the entire assembly carried by the annular mountingplate 8 may be rotated into a vertical position and secured in thisposition by tightening the cap screws I0. Alternatively the sleeve 3 maybe separated from the remainder of the structure and screwed into theboiler wall separately after which the mounting plate 8 and the partscarried thereby may be secured adjacent the flanged open end of thesleeve 3 by means of the annular ring 9 and cap screws I0.

The sleeve I5 might have substantially its entire inner end open for theentry of the denser water but the arrangement shown provides cptimumeffect according to my experience. For best results the openings 32 inthe outer end should be only at the lower side of the casing l so as toinsure that the flow will carry out solids along the bottom wall wheresuch solids are most likely to accumulate and block the lowering of theiioat. Blocking of the float against lowering may produce dangerousconditions.

It will thus be seen that my invention has overcome in the particularinstance described, the chief objection to installing a float controldirectly in the side wall of a boiler. It will be understood, however,that the invention is not limited to the specific embodiment abovedescribed since the invention may be incorporated with widely differentdevices, but utilizing the teaching of my invention.

I claim:

1. A self-cleaning boiler control or the like comprising in combination,a tubular shield for housing a control member and adapted to be mountedin the wall of a boiler with one end disposed within said boiler andwith the other end disposed outwardly of said boiler, said tubularshield having a circulation directing opening at said one end in thelower portion thereof and a circulation directing opening at said otherend, there being a passageway extending from said boiler to thecirculation directing opening at said other end whereby water from theboiler is caused to flow through said passageway into the circulationdirecting opening at said other end of said v tubular shield, thencethrough said tubular shield substantially along the bottom insidesurface thereof, and thence out of the circulation directing opening atsaid one end of said tubular shield back into said boiler.

2. A self-cleaning boiler control or the like comprising in combination,an elongated tubular shield of substantially oblong cross-section forhousing an elongated substantially cylindrical float, and means formounting said tubular shield in the wall of a boiler with its majorcross-sectional axis disposed substantially vertically for allowing saidfloat to move in a substantially vertical plane, said means beingadapted to support said tubular shield with one end of the latterdisposed within said boiler and with its other end disposed outwardly ofsaid boiler, there being a circulation directing opening at each end ofsaid tubular shield in the lower portion thereof, said tubular shieldand said means defining a passageway from said boiler to the circulationdirecting opening at said other end of said tubular shield whereby waterfrom the boiler is caused to iiow through said passageway into thecirculation directing opening at said other end of said tubular shield,thence through -said tubular shield substantially along the bottominside surface thereof, and thence out of the circulation directingopening at said one end of said tubular shield back into said boiler.

3. In a boiler control or the like, the combination of an outersupporting sleeve member of substantially circular cross-section adaptedto be mounted in the wall of a boiler in communication therewith, and aninner tubular shield of substantially oblong cross-section the majorcrosssectional axis of which is substantially equal to the diameter ofsaid sleeve, said tubular shield having a circulation directing openingin the bottom thereof at each of its ends, said tubular shield beingarranged in said sleeve with said major cross-sectional axis disposedsubstantially vertically and with one end of said tubular shielddisposed within said boiler and with the other end of said tubularshield disposed outwardly of said boiler, said tubular shield and saidsleeve dening a passageway extending from said boiler to the circulationdirecting opening at said other end, whereby water from the boiler iscaused to iiow through said passageway into the circulation directingopening at said other end of said tubular shield, thence through saidtubular shield substantially along the bottom inside surface thereof,and thence out of the circulation directing opening at said one end ofsaid tubular shield back into said boiler.

4. In a boiler control or the like, the combination of an outergenerally horizontal sleeve member of substantially circularcross-section adapted to be mounted in an opening provided therefor inthe wall of a boiler and in communication therewith, an inner generallyhorizontal tubular member of substantially oblong cross-section themajor cross-sectional axis of which is substantially equal to thediameter of said sleeve, said tubular member being adapted to bedisposed within said sleeve with an end thereof extending inwardly ofsaid boiler wall, said tubular member being adapted to house a oat andhaving circulation directing openings adjacent its ends, and means foradjusting said tubular member so that said mai or axis is disposedvertically in said sleeve to allow said iioat to move in a verticalplane and to dene a passageway between said tubular member and saidsleeve whereby water from the boiler will flow between them and into thecirculation directing opening at the end of said tubular member oppositesaid end disposed inwardly of said boiler through said tubular membersubstantially along the bottom of the inside wall thereof, and then outof the circulation directing opening at the end thereof extendinginwardly of said boiler wall.

5. In a boiler control or the like, the combination of an outer sleevemember of substantially circular cross-section adapted to be mounted atone end in an opening provided therefor in the wall of a boiler, amounting member adjacent the other end of said sleeve, a tubular memberof substantially oblong cross-section having circulation openingsadjacent its ends and adapted to be supported within said sleeve by saidmounting member, said tubular member being adapted to house an elongatedsubstantially cylindrical float, and means for adjusting said mountingmember so that the major cross-sectional axis of said tubular member isdisposed vertically in said sleeve to permit said float to move in avertical plane, said tubular member and said sleeve dening passagewaysbetween them whereby water will iow through said passageways and intothe opening in one end of said tubular member through said tubularmember and then out of the opening at the other end thereof.

OSCAR F. CARLSON.

